Henry VIII had at least two sons with Catherine of Aragon, both named Henry, and both dying during early infancy.
The elder Prince Henry, if he had survived, would have been in his early thirties when Henry VIII died.
As mother of the Heir, Catherine's marriage would not have been repudiated that easily, if at all.
What would have been the repercussions of this son surviving to adulthood to become Henry IX and continuing the Tudor Dynasty?
Would the English Reformation take place? Or would we have an Inquisition as brutal to that of Spain's?
What about Mary? Would the plans of marrying her off to the Emperor or to the King of Scots take place?